U.S. Pat. No. 5,943,825 (Procton et al.) and U.S. Pat. No. 6,052,949 (Procton et al.) purport to disclose a building entryway system with a high degree of modularity to accommodate active inswing doors or inactive sidelight panels for use with conventional jambs. Specifically, an extruded aluminum sill is mated with an extruded polymeric receiving unit. The receiving unit defines a u-shaped channel which accepts a weather strip or panel cap. Either the weather strip or panel cap is slidably positioned within the channel under the door. Additionally a door sweep attached to the active doors sealingly engages the weather strip to prevent water from entering the building.